Collecting rainwater and storing it in a cistern for household use is not a novel concept. How much roof area and storage is needed? How should it be treated prior to consumption?
Rainwater was considered to be a generally clean source of water requiring minimal treatment for safe consumption (Thomas et al. 2014). A recent study (Cousins et al. 2022) reveals that PFAS contamination is now global, and untreated rainwater is no longer safe to drink anywhere on the earth. It is thus necessary to filter rainwater with a recommended process (US EPA 2018) for consumption.
But what about the impacts of PFAS on the natural environment, with no luxury of filtration before consumption?
The average annual precipitation in Anne Arundel county is 42.45 inches, with an average of 4.17±0.25 per month with a 95% CI 1. Note that there is a lot of variability. May of 2015 was about 1.5 inches, June 2015 was over 12.5 inches of rain.